We will study the role of an electrochemical proton gradient in oxidative phosphorylation. Methods for measuring the pH gradient and membrane potential in submitochondrial particles will be developed, and the energetics and kinetics of the proton gradient and ATP synthesis studied. Spectrophotometric membrane potential probes will be used for kinetic studies. The structure and mechanism of proton translocation by reconstituted cytochrome b-c1 complex will be studied. Kinetics of oxidation and reduction in the complex will be studied with a digital spectrophotometer and the results analyzed by computer simulation of several possible pathways. The glucose transport protein of red cells has been reconstituted into phospholipid vesicles. The protein will be purified using reconstitution into glucose permeability as the assay, and the protein characterized.